1. Heating potassium permanganate, the chemical formula is: 2KMnO4=heating=K2MnO4+MnO2+O2↑
Laboratory oxygen preparation device Figure 2. Use catalyst - manganese dioxide and heat potassium chlorate, the chemical formula is: 2KClO3=MnO2 catalyze and heat = 2KCl+3O2↑ (Some textbooks have been deleted) It is important to note that this reaction is actually an exothermic reaction, not an endothermic reaction. reaction. 2KClO3= 2KCl+3O2↑, the reaction heat is 108kJ3. The hydrogen peroxide solution generates O2 and H2O in the catalyst (mainly manganese dioxide, iron oxide, and copper oxide are also acceptable). The chemical equation is: 2H2O2=MnO2= 2H2O+O2↑ In addition, the decomposition of sulfur trioxide can also be used Oxygen is generated. The decomposition of hypochlorous acid, hypobromous acid and hypoiodous acid can also generate oxygen (2HCl(Br, I)O = heating or light = 2HCl(Br, I) + O2), and electrolyzed water (2H2O= Electrolysis = 2H2 + O2), you can also use potassium permanganate and hydrogen peroxide to react (almost not used). In the chemical poetry experiment, first check the air tightness and tilt the test tube evenly when heated. Collect common drainage methods, remove the pipe first and then move the lights. Explanation: 1. Check the air tightness first during the experiment, and heat the test tube evenly. Tilt the test tube: "Tilting the test tube" means that when installing a large test tube, the test tube should be slightly tilted, that is, the test tube mouth should be lower than the bottom of the test tube, so as to prevent heating. The small amount of water contained in the medicine turns into water vapor, condenses into water droplets at the mouth of the tube and flows back, causing the test tube to rupture. "Heating evenly" means that when heating the test tube, the test tube must be heated evenly. 2. Common drainage method for collection: This means that when collecting oxygen, the drainage and gas collection method should be used. 3. Remove the tube first and then move the lamp: This means that when stopping the oxygen production, you must first withdraw the air tube from the water tank, and then remove the alcohol lamp (if you remove the alcohol lamp first, the temperature inside the test tube will drop and the air pressure will drop. If it decreases, water will be sucked into the hot test tube along the conduit, causing the test tube to rupture due to rapid cooling) [3].